Chances are, if you use any sort of social network, you'll have been on one end or the other of some viral marketing. You might have been asked to join an army, or build a town hall, or research a new cheesecake topping.
Maybe you're a perp, a peddler. Maybe you're one of the voluntary marketeers, flinging requests at your social compatriots at a rate of knots. Perhaps you're starting to wonder why nobody talks to you any more.
If you're on Facebook, then you're more likely than not to have hidden, blocked or even deleted a 'friend' because they just won't shut the hell up about their damned vegetables or their sheep. Enough, after all, is enough.
"Where there's that sort of opportunity there's bound to be someone who'll take advantage of it to the greatest extent that the market can bear"
But even if you're not a fan of having your social feeds flooded with requests, you've probably clicked a few here and there amongst the dismissals, perhaps discovered a game which you've ended up playing, enjoying or even monetising.
Two clicks and you never have to hear from a game again. So why does anybody listen at all?
Viral marketing is, to a large extent, becoming a victim of its own success. For a brief and golden period, viral marketing for social games was the philosopher's stone of advertising. It turned every user into a billboard, a radio beaming ad content into the eyelines of friends and family.
Exponential, effective and almost free.
As Alexis Kennedy, head of Failbetter Games and joint creator of interactive social story-telling game Fallen London (nee Echo Bazaar), points out, never before had there been such an incredible opportunity to expand an audience with such low expenditure.
"Somebody said a while ago that there has never been, in the history of the human race, an opportunity to acquire customers cheaply and quickly in the way there was in the early days of Facebook," Kennedy explains.
"If you look back at how aggressive very early applications were, and Zynga is notorious for this although they're far from the only ones, it's extraordinary the growth and speed. Where there's that sort of opportunity there's bound to be someone who'll take advantage of it to the greatest extent that the market can bear. Once there's one person doing it, there are bound to be others."
It's a beguilingly simple and rewarding model. Engage your player, tap them for a little cash, perhaps. Once they're on board, start offering something they might normally pay for in exchange for a little leg work. You get new users, the player gets new friends and content, and more people hear about your amazing game.
So would you, as Kennedy has now done, decide to move away from that model, removing the necessity of social logins for Fallen London completely in a recent relaunch and adding an email only option instead.
"When I first got Echo Bazaar," Kennedy continues, "I wanted to build something that told a story in little chunks over days, weeks, months. I chose to make it a social game, because that's what people did in 2009. It also seemed like a sensible way to get some cheap viral advertising.
"We always thought, 'we won't be very aggressive, we'll be polite and we won't knock much of the game off if you don't bring in your friends. We'll be very cautious about infiltrating people's Facebook and Twitter streams. Plus the content will be so great that people will share it by word of mouth.'"
It's a familiar story. Nobody sets out to become an annoying viral advertiser. Peppering people with requests so often that they block your application is obviously counter-productive, but as Kennedy points out, every piece of viral advertising is also a potential ad spend which Facebook loses from its inventory.
"The thing is, aggressive viral advertising works better than non-aggressive viral advertising."
Nonetheless, says Kennedy, being intrusive can bring results, if you can galvanise yourself and take the flak it generates.
"The thing is, aggressive viral advertising works better than non-aggressive viral advertising. We ended up being presented as a social game which did aggressive viral things, but we were never really comfortable with it."
Fallen London isn't your typical social title. Featuring over 700,000 words of content, which Kennedy tells me is more than War and Peace or Lord of the Rings, but just shy of the King James Bible, the reward mechanic pays out in prose, not points.
As a game which engages its players with narrative and imagination, rather than coins, battleships or hats for donkeys, Fallen London is already in the social gaming minority. Add to that the fact that around 75-85 per cent of it can be accessed for free and with no Facebook or Twitter credentials and you may start to wonder whether Kennedy has a head for business at all.
But Fallen London monetises well, selling Fate points which unlock story arcs and new narrative options, adding new turns to it's well-crafted narrative labyrinth. Player retention is excellent, Kennedy says, and attracts well-educated, well-read 20-45 year olds with the recreational cash to spend on a good yarn.
For Kennedy, viral options were always just that, optional. But until recently players still had to use either Twitter or Facebook to sign up for Fallen London, putting their login details into the hands of Failbetter Games and hoping they were as good as their word. Now, all they need is an email account.
"We never reaped the benefits that more aggressive companies did," says Kennedy of the company's early experiences with viral marketing, "but at the same time, every time someone came to the site and saw that you had to give up your Facebook or Twitter credentials, we looked as potentially invasive as anyone else.
"So we just said, hang it all. There's still some of the old stuff left in there because it's easier to leave it in that take it out, but you can now sign up with just an email. It can be a junk email if you don't trust us.
"Once we made that leap we realised how little we were giving up, unless we were prepared to be aggressive, which we're not."
"Once we made that leap we realised how little we were giving up, unless we were prepared to be aggressive, which we're not. By allowing people to sign up with that sort of token, and email is the one that they're used to, you show that you're not that bothered about giving up the virals, so it's kind of a show of good faith.
"The more I think about it in those terms, the more I like it."
You might be forgiven for thinking that Kennedy sees viral as inherently evil, but that's far from the case. Acknowledging the usefulness of social network access for metric research, Kennedy says that it's still disappointing that keying into private information has become such a default requirement. The current system, he feels, is open to abuse.
"Twitter and Facebook are quite different," Kennedy explains when I ask him what sort of options developers have about the permissions their games request.
"Twitter is basically all or nothing. There's one extra level of permission on Twitter that you can authorise, which is the ability to see the direct messages people have sent and received. If you ask for the basic level of authentication on Twitter you can post as that person, you can send direct messages as that person.
"It'll flag that your application was used to send this, you can't pretend that the user typed the text, but technically you could be abusive. Of course, Twitter will clamp down on you, but it's all about the stuff that's borderline abuse, really.
"Facebook has much finer granularity, you can decide if you want something to post to your timeline on your behalf. But Facebook are always changing stuff about. Notoriously, people don't understand the Facebook privacy model. It's very hard to work out what people can and can't see, what things will and won't do on your behalf."
"Facebook are always changing stuff about. Notoriously, people don't understand the Facebook privacy model"
It's a system which operates on trust, with increasingly diminishing returns. By granting an app or game access to you social network, players are intrinsically putting their belief in the creator's marketing skill and judgement.
Kennedy sees it as analogous to handing out your home phone number.
"If I give someone my home phone number, maybe they won't use it at all," he explains. "Maybe they only use it to tell me a relative has been involved in an accident. Maybe they ring me every three hours to try and sell me content protection insurance.
"You can revoke permission to applications at any time, but that's closing the stable door in some cases. If your feed is full of stuff, you can delete stuff, or you ask people to hide it, or say the app went rogue, but it's still embarrassing. It's not apocalyptic, you've not let someone into your house to steal your stereo, but it is socially embarrassing and awkward and it damages trust."
Lessons, says Kennedy, are being learned, on both sides of the developer and platform divide.
"It has started seeing a decline. It's much harder for a social game companies to acquire customers on Facebook than it used to be. Facebook is constantly tweaking parameters and trying to make it easier because they don't want to kill the goose that lays the golden egg, but harder because they don't want to drive their users away.
"I don't think the age of it is passed, sadly. I think these things are here to stay, but I don't think it's the Wild West that it was."
"The thing they're trying to do most of all is to segregate people who like these sorts of games and invitations from people who don't, but of course it's not that straight forward - I might love hidden object games but hate social RPGs, or vice versa.
"I don't think the age of it is passed, sadly. I think these things are here to stay, but I don't think it's the Wild West that it was. It's like the 1920's, we still have gangsters and pitched battles in the street but there is at least a law in town."